Pierre Landry Kabore's double helped Hearts sweep aside undisciplined nine-man Dundee United and move seven points clear at the top of the Scottish Premiership.
Kabore tapped home the opening goal on 11 minutes after superb work down the left flank from Harry Milne, and the visitors then profited from two video assistant referee (VAR) interventions before half-time.
First, Don Robertson advised referee Calum Scott to have a second look at a challenge by United winger Amar Fatah on Hearts midfielder Marc Leonard. The initial yellow card was upgraded to red and the hosts were reduced to 10 men.
Things went from bad to worse for the home side five minutes later when Claudio Braga was fouled by Ryan Strain and VAR Robertson intervened to advise the incident was in the box.
Alexandros Kyziridis found the bottom corner, sending debutant goalkeeper Ashley Maynard-Brewer the wrong way.
From there, the result was never really in doubt as Hearts dominated proceedings.
They flooded forward time and time again in the second half and the third goal would have come far sooner were it not for Maynard-Brewer.
Kabore was twice denied by excellent saves, Milne had a drive tipped over the bar and Tomas Magnusson put a free header off target.
United's cause was not helped by substitute Panutche Camara motioning his head towards Leonard, leaving his team with nine players for the final 15 minutes, with coach Dave Bowman also sent to the stands for his protests.
Kabore's deflected strike made it three in the closing stages as the league leaders threw down the gauntlet to their Old Firms chasers.
Derek McInnes' side are seven clear of Rangers and nine clear of Celtic, who face Hibernian and Falkirk, respectively, on Sunday.
